Electro-mechanical transducer for cleaning



Oct. 5, 1965 A. E. GAAL ELECTED-MECHANICAL TRANSDUCER FOR CLEANING Filed March 27, 1964 INVENTOR ANDREW E. GAAL W KW AT TORNEV United States Patent tion of Pennsylvania Filed Mar. 27, 1964, Ser. No. 355,380

8 Claims. (Cl. 259-72) This invention relates to a mechanical means for producing ultrasonic vibrations which, transmitted to a body of liquid in the pan of a washing receptacle, may be employed for cleansing purposes.

The object of the invention is to provide a simple and economical means to produce ultrasonic mechanical vibrations.

In accordance with this invention an annulus consisting of a plurality of U-shaped laminations of material having magnetostriotive properties is aflixed to the underside of a pan or receptacle for holding the cleansing liquid and a plate bearing an annulus consisting of an equal number of permanent magnets fixed in close proximity thereto is revolved at high speed whereby, through magnet-ostriction effects produced in said laminations through the movement of said magnets, a vibration is produced in the bottom of said pan and this is transmitted to the liquid therein. The laminations are each afiixed to the bottom of the pan and each depends therefrom in a plane at right angles to the bottom surface of the pan and their ends thus present a virtual surface parallel to the said bottom surface of the pan. The said plate, in the surface of which the permanent magnets are embedded, is rotated by a motor and its surface is parallel and contiguous to said virtual surface formed by the end edges of said laminations. The magnetostrictive mechanical movement produced in each lamination as each magnet approaches, passes and moves away fro-m its end surface and constitutes a mechanical vibration which is transmltted to the liquid within the pan. The laminations and the spacing of the magnets are adjusted so that the approach, the passing and the movement away from each group of laminations by the said magnets is simultaneous whereby the vibrations may be said to be produced by a mass movement of the laminations.

It is known that when these vibrations are in the ultrasonic range, say in the neighborhood of twenty thousand per second, soils and debris clinging to objects submerged in this liquid will be loosened and cleansed away.

Where, by way of example, the face of the said laminations contains sixty groups, each three degrees in width with a space of three degrees between adjacent groups and the said permanent magnets embedded in the surface of the disk to be revolved before this face of laminations are each three degrees in width with a space of three degrees between adjacent magnets, it will be understood that in the mechanical movement of the disk that at a given point in the revolution thereof each magnet will exactly confront a corresponding group of laminations and that in three degrees of revolution thereafter each magnet will have attained a position exactly halfway between two groups of laminations. 'It will be understood that a magnet in moving from a position exactly halfway between two groups of laminations, past one said group of laminations to a position exactly halfway between the next two groups of laminations will magnetically affect said one group of laminations from a minimum to and through a maximum and thence to a minimum effect and this group of laminations being constructed of magnetostrictive material will, in this six degrees of travel of the said disk, respond by a mechanical movement as a result of magnetostrictive distortion. Thus, each of the sixty ice groups of laminations will simultaneously produce a mechanical movement which may herein be characterized as a pip and in one complete revolution of said disk, a train of sixty pips will be produced. Now, if the said disk is rotated at the rate of twenty thousand revolutions per minute, the surface of the pan to which the said laminations are ailixed will be subjected to a train of mechanical vibrations at the rate of twenty thousand pips per second. This is in the ultrasonic range employed for ultrasonic cleaning.

A feature of the invention is the division of the figure representing the ultrasonic frequency into two factors, one of which represents the number of vibrations produced in each revolution of the disk in which the bar magnets are embedded. In the example hereinbefore cited, this number is sixty, which means that considering a single bar magnet, it passes before sixty armatures in each revolution and thereby induces a magneto-strictive effect in each, or a train of sixty such effects. By embedding sixty such bar magnets in the face of such disk, there will still be sixty magnetostrictive effects produced per revolution, but each such effect will be the result of sixty bar magnets simultaneously passing sixty armatures and this fortified effect is distributed evenly over the bottom face of the receptacle to which the armatures are secured.

In accordance with this feature, the rotating disk at each six degrees of rotation confronts a mirror image of its arrangement of bar magnets in the arrangement of armatures, excepting that the magnet presents an oblong face whereas the armature presents a pair of smaller square faces whose general outline is an equally dimensioned oblong area.

A feature of the invention is an annulus of armatures for a correspondingly arranged annulus of permanent magnets mounted on a disk which may be rotated at high speed in close contiguity to the surface of said annulus of armatures. Said armatures are constructed of magn-etostrictive material so that as each is magnetized by the passage of a magnet before its face the mechanic-a1 movement constituting its magnet-ostrictive response will be transmitted :as a mechanical vibration to the body to which it is affixed.

The usual form for a permanent magnet and its keeper is a U-shaped magnet whereby it is known as a horseshoe magnet and a straight bar for the keeper or armature. Herein the forms are reversed and the magnet is a bar and the keeper or armature has a horseshoe shape. In accordance with the present invention the horseshoe armature is in the form of a group of thin laminations and these are secured at their midpoints to the under surface of the cleansing receptacle so that each is dependent therefrom. As a bar magnet passes the lower ends of one of these horseshoe armatures su-c'h armature becomes magnetized, and being constructed of magnetostrictive material, responds with a mechanical deformation from which arises a vibration. Where the speed of rotation of the disk of bar magnets is high enough an ultrasonic vibration is set up in the receptacle and in the liquid contained therein.

It will be understood that where the disk bearing thev bar magnets is left at rest in close contiguity to the said face of said horseshoe armatures, the magnetic properties of said bar magnets will hold said magnets closely in alignment with said armatures and that it will require. considerable power to start said disk into rotation. In accordance with this invention the said disk is backed off from the face of said armatures so that the starting torque will be very greatly reduced and after the speed of revolution of the disk has been brought up to its operating value then means are employed to move the disk toward the face of the armatures to render the con-frontation of the armatures by the bar magnets effective. A feature of the invention therefor resides in a control, effective when the speed of rotation desired has been attained, to move the face of the disk in which the magnets are embedded into close contiguity with the face of the plurality of armatures so that the simultaneous mechanical effects produced in each will be transmitted as a train of ultrasonic vibrations.

In one form this means is shown as a mechanical lever whereby the face of the magnet bearing disk may be moved along splines constructed in the shaft of the motor used for turning the disk so that such disk may be made to approach the plane of the ends of the horseshoe armatures whereby the sum of the simultaneous magnetostrictive effects produced will transmit into the liquid in the receptacle a train of ultrasonic vibrations of sufiicient strength for this ultrasonic cleansing.

Another feature of the invention is the manner in which said bar magnets are disposed to confront said armatures. Each bar magnet is affixed to the face of the disk so that both its poles are at surface level and all of said bar magnets are oriented along .a radius of the circular disk. All of the said bar magnets are poled alike, that is, all outward ends of said bars have the same pole and likewise all inward ends thereof have the opposite pole. By such an arrangement the train of mechanical vibrations produced by the mass magnetostrictive movement of the armatures will constitute a train of positive pulses rather than a succession of positive and negative pulses.

\Another feature of the invention is a revolvable disk of non-magnetic and non-conducting material in which a plurality of bar magnets are embedded in such manner that the faces thereof are in a plane perpendicular to the axis of rotation. The material used may be any plastic of sufiicient strength to withstand the high speed rotation to which the disk is subjected and which will not magnetically or electrically affect the operation of these magnets.

Another feature of the invention is the distribution of a large number of magnet armatures on the bottom surface of the receptacle to cover this surface as evenly as possible with this mass effect. A plurality of annuli of dependent armatures and corresponding annuli of bar magnets may be used and such an arrangement will be effective where the spacing is carefully arranged so that the passage of each magnet before each armature produces its maximum effect simultaneously.

Other features will appear hereinafter.

The drawings consist of one sheet having four figure-s as follows:

FIGURE 1 is a schematic showing partly in vertical section indicating how an annulus of m-agnetostrictive armatures is fixed to the bottom surface of a cleansing receptacle and how a mirror image annulus of bar magnets embedded in the face of a revolvable disk is mounted on the splined shaft of a motor so that the face thereof may be lifted int-o close contiguity with the said armatures;

FIG. 2 is a view taken on line II-II looking upwardly at the annulus of dependent armatures;

FIG. 3 is a view taken on line IIIIII looking downwardly at the face of the rotatable disk showing the annulus of bar magnets embedded therein; and

FIG. 4 is a perspective view of the armatures and the bar magnets showing how the series of magnetostrictive impulses are developed as the bar magnets move.

The device of the present invention consists of a receptacle 1 shown here as fitted into the face of a table or bench 2. The receptacle 1 may be filled to any desired depth with water or any other liquid which may be used to cleanse soiled objects. To the bottom of this receptacle there is affixed in any conventional manner an annulus 3 of horseshoe magnet armatures 4. These armatures thus depend from the bottom surface of the receptacle and their bottom faces combined constitute a plane surface parallel to the bottom face of the receptacle 1. There is then provided a motor 5, mounted in any conventional manner to be stationary with respect to the receptacle 1. This motor has a splined shaft 6 by which a disk 7 may be rotated and in whose upper face an annulus of bar magnets 8 may be embedded or to whose upper face these bar magnets may be affixed in any conventional manner. The bar magnets may be embedded into a non-magnetic, non-conducting disk of glass-laminate or nylon phenolic material and may be mounted in one or more concentric rings or annuli. In the drawings only a single annulus of dependent armatures and a single annulus of bar magnets is shown, but it will be understood that concentric annuli may be provided to render the mass effect of a large number of simultaneous magnetostrictive effects generally applied to the bottom surface of the receptacle 1.

In the perspective showing, FIG. 4, it is indicated that in the rotational movement of the disk 7 as each magnet moves from a position exactly midway between two adjacent armatures where the magnetic effect on the armatures it is passing is at a minimum, to a point where such magnet is exactly lined up with an armature where such magnetic effect is at a maximum and thence to the next minimum, the magnetostrictive effect produced may be represented as a series of positive pi-ps 9. By way of example, if the annulus of dependent armatures and the annulus of embedded magnets each contain sixty individual pieces, evenly spaced at six degrees then in one complete revolution of the disk 7, there will be developed a train of sixty pips 9 and each pip will be represented by the mass effect of sixty magnetostrictive responses by all of the said armatures, If the motor 5 moves its shaft 6 at the rate of 20,000 revolutions per minute then the train of pips or magnetostrictive responses will be at the rate of twenty thousand per second which is within the ultrasonic range used for ultrasonic cleaning.

As indicated in FIG. 2, each horseshoe armature is constructed of a plurality of thin laminations of magnetostrictive material, such as a suitable alloy of iron or nickel. These horseshoe armatures depend from the bottom surface of the receptacle 1 and their mass effect is to transmit an ultrasonic vibration into the liquid contained in this receptacle.

Since the mass effect of the large number of magnets at rest facing an equal number of armatures over a minimum gap will be an effective lock so that to start the disk 7 into rotation would require considerable power, means in the form of the connection of the disk 7 to the shaft 6 through splines is provided. By a clutch handle 10, the disk 7 may be backed off from the face of the annulus of armatures until the proper speed of rotation has been attained. The operating position of the handle 10 and the disk 7 is shown in full, while the starting position is shown in outline.

The coupling between the motor shaft 6 and the disk 7 need not be confined to the splined shaft arrangement, but may be any other convenient flexible coupling.

What is claimed is:

1. A receptacle in which soiled objects may be submerged in liquid for cleansing, having affixed to the outer bottom surface thereof an annulus of dependent magnetostrictive magnet armatures, the lower surfaces of said armatures constituting a flat surface in a plane parallel to the said outer bottom surface of said receptacle, a disk having a plane surface, mounted closely contiguous to said surface of said armatures, means to revolve said disk about an axis perpendicular to said contiguous surfaces and an annulus of bar magnets embedded in and constituting said surface of said disk.

2. A receptacle in which soiled objects may be submerged in liquid for cleansing, having afiixed to the outer bottom surface thereof an annulus of dependent magnetostrictive laminations constituting a plurality of armatures each for a permanent magnet, a disk having an annulus of bar magnets embedded in the surface thereof mounted for revolution beneath said annulus of armatures and motor means for revolving said disk at speeds sufficiently high to translate the vibrations resulting from the magnetostrictive response of said armatures into an ultrasonic effect for cleansing said soiled objects.

3. A receptacle in which soiled objects may be submerged in liquid for ultrasonic cleansing, having affixed to the outer bottom surface thereof an annulus of dependent magnetostrictive magnet armatures, the lower surfaces of said armatures constituting a flat surface in a plane parallel to the said outer bottom surface of said receptacle, a disk having a plane surface, mounted closely contiguous to said surface of said armature, means to rotate said disk about an axis perpendicular to said contiguous surfaces, and an annulus of bar magnets embedded in and constituting said surface of said disk, said dependent magnet armatures being placed at regular intervals in said annulus and said bar magnets being equal in number to said magnet armatures whereby at every rotational position of said disk to a point where a said magnet exactly confronts a said armature the pattern of the confrontation of said armatures by said magnets will be the same.

4. A receptacle in which soiled objects may be submerged in liquid for cleansing, having affixed to the outer bottom surface thereof an annulus of dependent magnetostrictive magnet armatures each oriented along a radius of said annulus, the lower surfaces of said armatures constituting a fiat surface in a plane parallel to the said outer bottom surface of said receptacle, a disk having a plane surface mounted closely contiguous to said surface of said armatures, means to revolve said disk about an axis perpendicular to said contiguous surfaces and an annulus of bar magnets embedded in and constituting said surface of said disk, said bar magnets each being oriented along a radius of said annulus, said annulus of armature faces in spacing and positions confronting a mirror image in said annulus of bar magnets.

5. A receptacle in which soiled objects may be submerged in liquid for cleansing, having affixed to the outer bottom surface thereof an annulus of dependent magnetostrictive magnet armatures each oriented along a radius of said annulus, the lower surfaces of said armatures constituting a flat surface in a plane parallel to the said outer bottom surface of said receptacle, a disk having a plane surface mounted closely contiguous to said surface of said armatures, means to revolve said disk about an axis perpendicular to said contiguous surfaces and an annulus of bar magnets embedded in and constituting said surface of said disk, said bar magnets each being oriented along a radius of said annulus and each being poled in the same direction.

6. A receptacle in which soiled objects may be submerged in liquid for cleansing, having aflixed to the outer bottom surface thereof an annulus of dependent magnetostrictive magnet armatures, the lower surfaces of said armatures constituting a flat surface in a plane parallel to the said outer bottom surface of said receptacle, a disk having a plane surface, mounted closely contiguous to said surface of said armatures, said armatures being placed at regular intervals along the periphery of said annulus, an annulus of bar magnets embedded in the face of said disk equal in number to said armatures and placed at like regular intervals along the periphery of said annulus of bar magnets, means to revolve said disk about an axis perpendicular to said contiguous surfaces whereby at regular intervals each of said bar mag nets will pass in close contiguity to a corresponding magnet armature and whereby the simultaneous magnetostrictive response of said armatures produces a mass vibration transmitted to said bottom surface of said receptacle and thence to a liquid contained thereby.

7. A receptacle in which soiled objects may be submerged in liquid for cleansing, having affixed to the outer bottom surface thereof a plurality of dependent magnetostrictive magnet armatures, the lower surfaces of said armatures constituting a fiat surface in a plane parallel to the said outer bottom surface of said receptacle, a disk having a plane surface mounted on a plane parallel to said surface of said armatures, said disk bearing a like plurality of bar magnets, means to revolve said disk about an axis perpendicular to said contiguous surfaces, said last means consisting of a motor having a splined shaft and said disk movable along said splined shaft and means to move said disk along said shaft to a position where said parallel surfaces are brought closely contiguous to each other.

8. A receptacle in which soiled objects may be submerged in liquid for cleansing, having aflixed to the outer bottom surface therof a plurality of dependent magnet armatures each constructed of a plurality of laminations of magnetostrictive material, the lower surfaces of said armatures constituting a flat surface in a plane parallel to the said outer bottom surface of said receptacle, a disk having a plane surface, mounted for movement in a plane parallel to said flat surface of said armature ends, bar magnets aflixed to said surface of said disk, means to place said disk in movement and means to move the moving face of said disk closely contiguous to said face of said armatures.

References Cited by the Examiner UNITED STATES PATENTS 3/59 Toulmin 259-72 10/64 George 25991 References Cited by the Applicant UNITED STATES PATENTS 2,468,837 5/49 Peek. 2,723,386 11/55 Camp. 

1. A RECEPTACLE IN WHICH SOILED OBJECTS MAY BE SUBMERGED IN LIQUID FOR CLEANSING, HAVING AFFIXED TO THE OUTER BOTTOM SURFACE THEREOF AN ANNULUS OF DEPENDENT MAGNETOSTRICTIVE MAGNET ARMATURES, THE LOWER SURFACES OF SAID ARMATURES CONSTITUTING A FLAT SURFACEIN A PLANE PARALLEL TO THE SAID OUTER BOTTOM SURFACE OF SAID RECEPTACLE, A DISK HAVING A PLANE SURFACE, MOUNTED CLOSELY CONTIGUOUS TO SAID SURFACE OF SAID ARMATURES, MEANS TO REVOLVE SAID DISK ABOUT AN AXIS PERPENDICULAR TO SAID CONTIGUOUS SURFACES AND AN ANNULUS OF BAR MAGNETS EMBEDDED IN AND CONSTITUTING SAID SURFACE OF SAID DISK. 